2-(omicron, omicron-dialkylphosphoro-dithioyl-methylmercapto)-carbamates and carbanilates



United States Patent This invention relates to certain novel chemicalcompounds and to the use of such compounds as insecticides andacaricides. The compounds are particularly valuable for their systemicand miticidal properties. More specifically, the invention relates tocompounds of the formula:

wherein R is a lower alkyl radical, R and R are selected from hydrogen,phenyl, and lower alkyl radicals.

The compounds of the present invention can be made in accordance withthe following illustrative examples (code numbers have been assigned toeach compound and are used hereinafter for convenience);

EXAMPLE 1 12-4243 -2-(0,0-diethylph0sphor0dithioylmeihylmercapt0)-ethylcarbamate An amount (19 g.) of2-(0,0-diethylphosphorodithioylmethylmercapto)-ethanol, prepared byrefluxing 23 g. of S-chloromethyl-0,0-diethylphosphorodithioate with g.of sodium hydroxyethylmercaptide in 150 ml. of ethanol for three hours,was allowed to react with an excess of phosgene in 50 ml. of chloroform.After four hours the excess phosgene, as well as the hydrogen chloride,were moved by means of a rotary evaporator.

The resulting solution was treated with excess anhydrous ammonia at atemperature less than -C. The resulting mixture was washed with waterthree times. The solvent was removed in a rotary evaporator. Thereremained 14 g. (64%) of crude product. The product was purified byextracting with cyclo hexane four times. In tlr's way 11.5 g. ofpurified product, n 1.5418, and 2 g. of impurities, 71 1.5223, wereobtained. A portion of the product was purified further bychromatographing it on a magnesium silicate column using progressivelymore polar solvents. The material in the center cuts proved to beessentially pure R-4243, 71 1.5460. The infrared spectrum of thechromatographed product contained bands for N-H (2.8-9/L), C=O (5.8 andbands for (9.3, 9.9, 10.4, 12.1 and 12.7,). )AnaL: Calc. forC3H13NO4PS3: C, H, N, 4.39%. Found: C, 30.19%; H, 5.58%; N, 4.59%.

EXAMPLE 2 R-4540-2- (0,0-diethylphosphorodithioylmethylmercapto) -elhylN ,N -dim ethy lcarbamate In the same manner as Example 1, 10 g. of2-(0,0

"ice

diethylphosphorodithioylmethylmercapto)-ethanol was allowed to reactwith excess phosgene and then excess dimethylamine to give, upon workingup, 10.6 g. (84%) of an amber liquid, n 1.5508.

EXAMPLE 3 R45412-(0,0-diethylphosphorodithioylmethylmercapto)-ethylN-ethylcarbamate In the same manner as Example 1, 10 g. of2-(0,0'-diethylphosphorodithioylmethylmercapto)ethanol was allowed toreact with excess phosgene and then excess ethylamine to give, uponworking up, 10.3 g. (82%) of an amber liquid, n 1.5320.

EXAMPLE 4 R-4542-2- 0,0-diethylphosphorodithioylmethylmercapto) -ethyl N-is0propy lcarbamate In the same manner as Example 1, 10 g. of 2-(0,0-diethylphosphorodithioylmethylmercapto)-ethanol was allowed to reactwith excess phosgene and then excess isopropylamine to give, uponworking up, 7.2 g. (55%) of a dark amber liquid, n 1.5263.

EXAMPLE 5 R45432- 0,0-diethylphosphorodithioylm ethylmercapzo -ethylcarbanilate An amount (8.4 g.) of2-(0,0-diethylphosphorodithioylmethylmercapto)-ethanol was allowed toreact with 3.6 g. of phenylisocyanate. The mixture became mildlyexothermic. was obtained 11.2 g. (93%) of a pale amber liquid, 111.5678.

EXAMPLE 6 R46622-( 0,0-diethylphosphorodithioylmethylmercapt0)-ethylN-butylcarbamate In the same manner as Example 5, 13.8 g. of 2-(0,0diethylphosphorodithioylmethylmercapto)-ethanol was allowed to reactwith 5.0 g. of butylisocyanate to give 16.8 g. (89%) of a pale amberliquid 11;, 1.5182.

The compounds have been tested as insecticides and as acaricidesaccording to the following methods:

Acaricidal evaluation test.The two-spotted mite, Tetranychus telarius(Linn) is employed in tests for acaricides. Young pinto bean plants areinfested with several hundred mites. Dispersions of test compounds areprepared by dissolving 0.12 gram of the toxic ma terial in tenmilliliters of acetone. This solution is then diluted with watercontaining 0.0175 v./v. of Tween 20, an emulsifier, the amount of waterbeing sufiicient to give concentrations of active ingredient rangingfrom 0.12% to 0.005%. The test suspensions are then sprayed on theinfested pinto bean plants. After seven and fourteen days, the plantsare examined both for post-embryonic forms of the mite as well as foreggs. The percentage of kill is determined by comparison with controlplants which have not been sprayed and the LD-50 value calculated usingwell-known procedures. LD-SO values are reported under the columns ZSMin After heating at C. for one hour there the table; PE indicates thepost-embryonic forms while B indicates eggs.

mine living and dead insects. The LD-50 values are calculated using wellknown procedures.

25M, 25M, Sys- Code HF Roach, per- MWB, per- CFB PE, 28M, E, temic, centcent perpercent p.p.m.

cent

.05 .05 1% .0l .0l 0.71 .05 .01 05 .O1 1% .0l .01 0.5

Systemic toxicity evaluation against two-spotted mites.-Pinto beanplants in the primary leaf stage are placed in 250 ml. capacityErlenmeyer flasks, one plant per flask. A portion of the test compoundis dissolved in 10 ml. of acetone. This solution is then diluted withdistilled water, the amount of water being sufficient to giveconcentrations of active ingredient ranging from one hundred parts permillion (pp-m.) to 0.1 part per million. The final volume of testdispersion per flask is 200 ml. The treated plants are infested withseveral hundred twospotted mites, T etranychus telarius (Linn). Theresults are reported in the table under 2SM Systemic.

After seven and fourteen days, the plants are examined both for postembryonic forms of the mite as well as for eggs. The percentage of killis determined by comparison with control plants which have been placedin distilled water only. Again, the LD-SO value is calculated andreported under the columns M Systemic" in the table.

Insecticidal evaluation tests-Four insect species are subjected toevaluation tests for insecticides:

(1) American cockroach (Roach) Periplaneta americana (4) Housefiy (HF)Musca domestica (Linn) The procedure for the insects is similar to therniticidal testing procedure. Test insects are caged in cardboardmailing tubes 3%" in diameter and 2%" tall. The mailing tubes aresupplied with cellophane bottoms and screened tops. Ten to twenty-fiveinsects are used per cage. Food and water are supplied in each cage. Theconfused flour beetle, however, are confined in petri 'dishes Withoutfood. The caged insects are sprayed with the active compound at variousconcentrations. After twenty-four and seventy-two hours, counts are madeto determine living and dead insects.

Housefiy evaluation tests differ in this respect: The toxicant isdissolved in a volatile solvent, preferably acetone, the active compoundis pipetted into a petri dish bottom, allowed to air dry and placed in,a cardboard mailing tube. Twenty-five female flies are caged in thetube. The flies are continuously exposed to the known residue of theactive compound in the cage. After twentyfour and forty-eight hours,counts are made to deter- The compounds of the present invention may beapplied to a pest habitat in ways well known to those skilled in the artsuch as dusts, sprays of solutions or dispersions and the like.

We claim:

1. A compound of the formula II II n onPsonzsomomoONR R:

wherein R is a lower alkyl radical, R and R is selected from the groupconsisting of hydrogen, lower alkyl radicals, and phenyl.

2. The compound 2 (0,0-diethylphosphorodithioylmethylmercapto)-ethylcarbamate.

3. The compound 2 (0,0-diethylphosphorodithioylmethylmercapto)-ethylN,N-dimethylcarbamate.

4. The compound 2 =(0,0-diethylphosphorodithioylmethylmercapto)-ethylN-ethylcarbamate.

5. The compound 2 (0,0-diethylphosphorodithioylmethylmercapto)-ethylN-isopropylcarbamate.

6. The compound 2 (0,0-diethylphosphorodithioylmethylmercapto)-ethylcarbanilate.

7. The compound 2 (0,0-diethylphosphorodithioylmethylmercapto) -ethylN-butylcarbamate.

8. The method of killing pests comprising applying to a pest habitat acompound of claim 1.

9. The method of killing pests comprising applying to a pest habitat 2(0,0-diethylphosphorodithioylmethylmercapto) -ethyl carbamate.

10. The method of killing pests comprising applying to a pest habitat2-(0,0-diethylphosphorodithioylmethylmercapto) -ethylN,N-dimethy-lcarbamate.

11. The method of killing pests comprising applying to a pest habitat2-(0,0-diethylphosphorodithioylrnethylmercapto)-ethyl N-ethylcarbamate.

12. The method of killing pests comprising applying to a pest habitat2-(0,0-diethylphosphorodithioylmethylmercapto)-ethylN-isopropylcarbamate.

13. The method of killing pests comprising applying to a pest habital2-(0,0-diethylphosphorodithioylmethylmercapto)-ethyl carbanilate.

14. The method of killing pests comprising applying to a pest habitat2-(0,0-diethylphosphorodithioylmethylmercapto) -ethyl N-butylcarbamate.

References Cited in the file of this patent UNITED STATES PATENTS2,981,748 Metivier Apr. 25, 1961

1. A COMPOUND OF THE FORMULA